chemometrics.mcr.constraint.ZeroCumSumEndPoints

class chemometrics.mcr.constraint.ZeroCumSumEndPoints(nodes=None, axis=- 1, copy=False)

Bases: Constraint

Enforce certain points in cumulative sum to be near-zero.

Reduces the cumsum baseline of data by piecewise subtraction of constant values between given nodes and the end points of the data. This approach is useful for first derivative data with localized peaks and no expected offset in the pure spectra. Each peak is delimited by a node.

Parameters

  • copy (bool) – Make copy of input data, A; otherwise, overwrite (if mutable)

  • nodes (list of int) – In addition to end-points, other points to ensure are approximately 0

  • axis (int) – Axis to operate on

__init__(nodes=None, axis=- 1, copy=False)

A must be non-negative

Methods

__init__([nodes, axis, copy])

A must be non-negative

transform(A)

Apply cumsum nonnegative constraint
transform(A)

Apply cumsum nonnegative constraint